i386/hvf: Integrates x2APIC support with hvf accel

i386/hvf: Integrates x2APIC support with hvf accel

Support for x2APIC mode was recently introduced in the software emulated
APIC implementation for TCG. Enabling it when using macOS’s hvf
accelerator is useful and significantly helps performance, as Qemu
currently uses the emulated APIC when running on hvf as well.

This change wires up the read & write operations for the MSR VM exits
and allow-lists the CPUID flag in the x86 hvf runtime.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Link: https://lore.kernel.org/r/20241105155800.5461-2-phil@philjordan.eu
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>